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Finding the Fourth Proportional to 871.63, 1,306.09 and 688.57

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Solution

The fourth proportional to 871.63, 1,306.09 and 688.57 is: 1,031.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.63 : 1,306.09 = 688.57 : x
  2. Step 2: Convert to fraction form
    871.63/1,306.09 = 688.57/x
  3. Step 3: Cross multiply
    871.63x = 1,306.09 × 688.57
  4. Step 4: Simplify right side
    871.63x = 899,334.39
  5. Step 5: Solve for x
    x = 899,334.39/871.63
  6. Step 6: Final answer
    x = 1,031.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.